Hand setting device for rotary response mechanisms in photographic cameras



Feb. 2, 1960 E. PFAFFENBERGER 2,923,170

' HAND SETTING DEVICE FOR ROTARY RESPONSE uacmmxsms IN PHOTOGRAPHIC CAMERAS Filed Nov. 12, 1958 Fig. 1

United States Patent HAND SETTING DEVICE FOR ROTARY RESPONSE MECHANISMS IN PHOTOGRAPHIC CAMERAS Erwin Pfalfenberger, Erlangen, Germany, assignor to P. Gossen & Co. G.m.b.H., Erlangen, Bavaria, Germany, a firm Application November 12, 1958, Serial No. 773,418

Claims priority, application Germany August 27,1958

8 Claims. (Cl. 74-625) This invention relates to exposure control in photographic cameras, and more specifically to a hand setting device by means of which indicating and control elements which are directly operated by a rotary response mechanism, can in addition be set by hand when particular circumstances demand. Such a case arises for example when, in order to obtain special desired effects,

the diaphragm blades of a camera are to be set by hand to a value which is other than that which corresponds to the prevailing lighting conditions and which is automatically set by the response mechanism.

- It is an object of the present invention to provide a hand setting device for a rotary response mechanism, which occupies only a small space, is simple in construction and which will effectively and efiiciently perform the purposes for which it is intended.

Another object of the invention is to provide a hand setting device which can be coupled to the rotary response mechanism in any position, thus rendering it unnecessary to first set the response mechanism or the hand 1 setting device itself back to their initial positions.

A further object is to provide a hand setting device which, by virtue of the'omission of a limitation of the angle of rotation, is of particularly advantageous construction, and in which the response mechanism is not mechanically overstressed during adjustment by hand.

Still another object of the invention is to provide a hand setting device which permits not only adjustment of the rotary response mechanism but'also a clamping action for retaining a setting obtained from the response mechanism.

According to the invention, a hand setting device for a rotary response mechanism accommodated in a housing and having current-responsive means rotatable in response to electric current fed to said response mechanism, comprises a cap-like member closing the housing at one of its ends and defining an aperture coaxial with the axis of rotation of the current-responsive means, an axially displaceable shaft projecting through said aperture, an adjusting knob mounted on the outer end portion of said shaft, an entrainer disc mounted on the inner end portion of said shaft, a pressure spring'surrounding said shaft between the cap-like member and the knob to urge said knob away from said cap-like member and said entrainer disc into engagement with said cap-like member, and a resilient arm attached with one of its ends to said rotatable current-responsive means and having a bent prism-shaped free end adapted to establish positive connection with said entrainer disc on axial displacement of said adjusting knob, shaft and entrainer disc against the action of said pressure spring.

The entrainer disc can have a flanged edge finely serrated like a crown wheel, or have a roughened border zone, to ensure a good entraining action of the free end of said resilient arm.

ice

As shown in Fig. 1, a core magnet current-responsive mechanism of ordinary construction, comprising an iron short-circuit cylinder 1, a core magnet 2, current feed spirals 3 and 4 and a rotary coil frame 5, has an axle 5a which connects the response mechanism to indicating and control elements (not shown) to be operated. The cylinder 1 forming a housing for the current-responsive mechanism is closed at one of its ends by a cap-like member 6. On the inner side of this cap-like member 6 there is arranged an entrainer disc 7 with a' finely serrated flanged edge 74: resembling a crown wheel. The rear side of this disc 7 bears against the inner side of the cap-like member 6 and the central portion of the retainer disc 7 is mounted on the inner end portion of a shaft 14 which passes through a central aperture in the cap-like member 6 and carries on its outer end portion an adjusting knob 9 loaded by a pressure spring 8 surrounding said shaft 14 between the cap-like member 6 and the adjusting knob 9.

The cap-like member 6 is provided with recesses 10 uniformly spaced on the periphery of a circle and in which protrusions 11 formed on the entrainer disc 7 resiliently engage.

A resilient arm 12 is fixed with one of its ends to the rotary coil frame 5 and has a bent over prism-shaped free end 13 located opposite the finely serrated edge 7a of the entrainer disc 7 at a short distance therefrom.

If the knob 9 is turned by hand, the protrusions 11' the rotary coil frame 5 and the indicating and controlelements connected therewith. The rotary response mechanism is released when the hand setting device is once again put into the rest position. If, in a response mechanism, a maximum angle of rotation of about is assumed, any desired angle within this 90 can be set because the recesses 10 and the protrusions 11 are arranged at a sector angle of in relation to each other.

The arm 12 is of such resilient construction and the serrations of the entrainer disc 7 are so fine that the prism-shaped end 13 of the arm 12 slides resiliently over the serrations when rotation of the coil frame 5 is prevented by a part of the response mechanism bearing against an end stop. As a result, the response mechanism is reliably protected against mechanical overloading without it being necessary to limit the angle of rotation of the knob 9 and the entrainer disc 7. 9

When the knob 9 of the hand setting device is turned to the left or right, the response mechanism is similarly turned without it being necessary to take into consideration the position the response mechanism has actually assumed in accordance with the current flowing therethrough.

It will be seen that the hand setting device gives not only an adjusting action on the rotary response mecha- 2,923,110 Patented Feb. 2, 196

nism and the associated indicating and control elements but also a clamping action forretaining asetting obtained In the' from the response mechanisnnor set by hand. embodiment shown in the drawing, it srmpiyrequrres finger pressure on the knob 9 against the pressure of the spring 8 to press the retainer disc 7'against the end 13' of thejarm 12 and so clamp the rotary coil frame in the;

viathetaxle 5a, will be set correctly in accordance with the measured light value. As'the photographer slowly traverses the camera upwardly. during the shot, in most cases the brightness of "the increasing amount of sky falling within the picture angle of the camera will exceed that ery of a circle and corresponding to recesses defined by said cap-like member, said protrusions being adapted to be forced out of said recesses,-when said adjusting knob is turned, to effect said axial displacement of said adjusting knob, shaft and entrainer; disc against the action of saidpressure spring.

5. A hand setting device for a rotary response inech-H 1 anism accommodated in a housing and having currentresponsive means rotatable in response to electric current due to the tower, so that the diaphragm aperture will automatically be made smaller. The result of this will be that theimportant part of the picture, namely the tower, will become increasingly under-exposed.

If on the other hand a' camera is used having a diaphragm'regulator incorporating a hand setting device in accordance with the invention, it is only necessary to apply ffinger pressureto the knob 9 at the beginning of the shot. In this way the automatic response mechanism is prevented from actuatingthe diaphragm during the progress of the shot and the diaphragm setting will remain the same during the shot in spite of the changing proportions of light. 7 1

. Instead of using a retainer disc having a flanged edge finely. serrated like a crown wheel, it is also possible to use a fiat'retainer disc having a, roughened border zone 7b, as shown in Fig. 2, for engagement with the prismshaped free .end 13 of the resilient arm 12.

It will, of course, be understood that various details of construction may be varied through a Wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

a I- claim: t 1 1. A hand setting device fora rotary response mesh ani'sm'accommodated in a .housing and having currentresponsive means rotatable in response to electric current current-responsive means, an axially displaceable shaft projecting, through said aperture, an adjusting knob mounted on the outer end portionof said shaft an entrainer disc mounted on the inner end portion of said shaft, a pressure spring surrounding said shaft between the cap-like member and the knob to' urge said knob away from said cap-like. member and said entrainer disc intoen'gager'nent with said cap-like member, and a resilient arm attached with one of its ends to said rotatable current-responsive means and having a bent prism-shaped free end adaptedto establish positive connection with said entrainer disc on axial displacement of said adjusting knob, shaft and entrainer disc against the action of saidpressure spring. I i v 2, -A hand setting'device as claimed in claim 1, wherein Zfinely serrated flanged edge isprovidedon the entrainer isc. I a

A hand setting device as claimed in claim 1, wheregnajroughened border zone tisiprovided on the entrainer 1sc. I i j 4. 'A hand'setting'device as claimedin claim 1, wherein the-iface of the entrainer disc adjacent-said cap-like .mem-

ber is provided with protrusions arranged on the periphfed to said response mechanism, comprising a cap-like member closing the housing at one of its ends anddefining an aperture coaxial with the axis of rotation of the current-responsive means, an axially displaceable shaft projecting through said aperture, an adjusting knob mounted on the outer end portion of said shaft, a circular entrainer member mounted on the inner end portion of said shaft, a pressure spring surrounding said shaft between the cap-like member and the knob to'urge said knob away from said cap like member and said entrainer member into engagement with said cap-like member, and a resilient arm attached with one of its endsto said rotatable current-responsive means and hav ing a free end adapted to establish positive connection with said entrainer member upon axial displacement of said adjusting knob, shaft and entrainermernber against the action of said pressure spring.

- 6; Apparatus for manually setting a rotary camera shaft projecting through said aperture, manual adjust ing means mounted on theouter end portion of said shaft, an entrainer disc mounted on the inner end portion of said'shaft, resilient means for urging said shaft in an axial direction outwardly with respect to the housing, andga resilient member attached at one of its ends to said rotatable current-responsive means and having a free end adapted to establish positive connection with said entrainer disc upon axial displacement of said manual adjusting means, snatt and entrainer disc, agamst the acrlon' ofsaid resilientrncans;

7. Amanual setting device, for a rotary response mechanism in a housing including camera diaphragm operating means rotatable in response to an electriccurrent fed thereto; comprising an axially displaceable-shaft in I alignment with theaxis of rotation of said current-re sponsive means and-projecting through an aperture in said housing, an adjusting handle mounted on the outer end portion of said shaft, a circular entrainer member mountedncoaxially with said shaft, means including a pressure spring surrounding said shaft for urging said shaft, handle and entrainer member awayf-rom said rotatablemeans, and alresilientarm'member, one of said members being fixedly mounted on said shaft and the other of said members being fixedly mounted on said rotatable means, said resilient arm member having a bent free end adapted to establish positive connection with said entrainer member upon axial displacement of said adjusting handle, shaft and-entrainer member against 1 the action of said pressure spring.

8-. A manual setting device according to claim 7, wherein said entrainer member has a roughened circular zone :and the free end of said resilient arm has means thereonfor positively engaging said roughened zone.

References Cited in the file of this patent UNITED STATES PATENTS Italy Mar. 4, 1954 

